[Android] Short-circuit touch forwarding when no touch handlers exist
Rather than forwarding the touch event to the input router and incurring the
attendant overhead, short-circuit touch forwarding from ContentViewCoreImpl
when no touch handler exists. This aligns with existing Aura behavior, and
saves ~20us/event when no touch handler exists.
BUG=341613
Review URL: https://codereview.chromium.org/
217253002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@260381 0039d316-1c4b-4281-b951-d872f2087c98